oral Depository t>4o/ w-'-vrrnrnent Documents f !fJ : I-Dionia Department of L EXTRATERRESTRIAL INTELLIGENCE RESEARCH SPACE SCIENCE AND APPLICATIONS Of B E F O R E T H E SUBCOMMITTEE ON O F T H E COMMITTEE ON SCIENCE AND TECHNOLOGY U.8. HOUSE (If REPRESENT AT fe s U.S. GOVERNMENT P R IN T IN G O F F IC E W ASHINGTON : 1979 September 19, 1978: Page Dr. Richard Berendzen, Provost, American University and Professor of Dr. Philip Morrison, Institute Professor and Professor of Physics, Massa chusetts Institute of Technology Dr. Noel Hinners, NASA, Associate Administrator for Space Sciences...... 43 Dr. George C. Pimentel, Deputy Director, National Science Foundation.... 58 Dr. A. G. W. Cameron, Chairman, Space Science Board, National Science September 20, 1978: David S. Heeschen, Director, National Radio Astronomy Observatory....... 73 Bernard M. Oliver, Vice President of Research and Development, Hewlett- EXTRATERRESTRIAL INTELLIGENCE RESEARCH TUESDAY, SEPTEMBER 19, 1978 U.S. Ho u s e o f Re p r e s e n t a t i v e s, Co m m i t t e e o n Sc i e n c e a n d Te c h n o l o g y, Su b c o m m it t e e o n Sp a c e Sc i e n c e a n d Ap p l ic a t io n s, Washington, D.C. The subcommittee met, pursuant to notice, in room 2318, Ray burn House Office Building, 10:07 a.m., Hon. Don Fuqua (chairman of the subcommittee) presiding. Mr. Fu q u a. The subcommittee will be in order. Without objec tion, permission will be granted for radio, television, and still pho tography to be taken during the course of the hearing. During the next 2 days, the subcommittee will review space research dealing with analyzing the radiation from space for evi dence of intelligent life beyond our planet Earth. As you are aware, NASA requested funding to initiate a program designated search for extraterrestrial intelligence in order to con duct a systematic study of the radio frequency spectrum for evi dence of intelligent transmissions from space. The House and Senate authorized $2 million for fiscal year 1979 for NASA to initiate the program. However, the House and Senate Appropri ations Committee have elected in conference not to provide any funds for this program. This subcommittee supported NASA's proposal to initiate the program in fiscal year 1979 in recognition of the importance of this new field of space exploration growing out of the science of ralio astronomy. Although the prospects for making contact may, indeed, be remote, a positive or even negative outcome can have significance on society substantially in excess of resources required to conduct the search. The whole idea of other intelligent beings existing beyond our planet is both fascinating and mind-boggling. It captures the imagi nation, not only of space scientists but of people throughout our Nation and the world. As one theologian has said in pondering the extent of the known universe, God certainly made a lot of matter, why not more intelli gence, more free beings, who, alone, can seek and know him. A number of highly qualified and distinguished scientists will appear before the subcommittee today and tomorrow to give their views on the subject. The subcommittee will have the opportunity to review the nature and scope of the program and examine the rationale, re- quirements, and issues associated with establishing, and m aintain ing a viable search capability. Our first witness this morning is Dr. Richard Berendzen, provost of American University and professor of astronomy. Following him we welcome Dr. Philip Morrison, the Institute Professor and Pro fessor of Physics at MIT. Then Dr. Noel Hinners, NASAs Associate Administrator for Space Science will be our last or wrap-up witness this morning. We will ask the witnesses to first present their testimony and then we will have questions after all of the testimony is completed. The House is going in session at 11 oclock. There will be a series of votes and a lengthy interruption shortly after that. We hope in this process the delays will be held to a minimum. Now, Dr. Berendzen, if you will proceed, we will be happy to hear from you. You may read your statement. STATEMENT OF DR BERENDZEN Dr. Berendzen. Mr. Chairman and members of the Subcommit tee on Space Science and Technology, I appreciate this opportunity to testify before you on the subject of SETTthe search for extra terrestrial intelligence. In the 19th century, Thomas Carlyle considered the stars and said: A sad spectacle. If they be inhabited, what a scope for misery and folly. If they be not inhabited, what a waste of space. Or, as Lee DuBridge, Science Adviser to President Eisenhower, put it: Either we are alone or we are not; either way boggles the mind. The quest for mankinds kin invariably prompts philosophical speculations. But on the basis of modern knowledge, what actually do we know about this esoteric yet enthralling subject? As recently as a generation ago, most scientists would have argued, often ex cathedra, that the likelihood is low that life exists beyond Earth. However, as M artin Rees has succinctly noted, Ab sence of evidence is not evidence of absence. And accumulating evidence during the last two decades has convinced many scientists world-wide that extraterrestrial life probably does exist, possibly in enormous abudance. It must be noted, however, that incontrovert ible proof has yet to be found: to date, the evidence is strictly circumstantial, but it is highly suggestive and possibly compelling. Today, the serious scientific search for extraterrestrial life com mands the attention and respect of many of our most prominent, careful, and judicious scientists. SETIin its sophisticated, modern formis solid and sober, not tawdry or sensational. Even for many informed skeptics, the question of the existence of extraterrestrial life has become not so much one of if as of where, and with regard to the search it has even become when, for ulti mate contact may be virtually inevitable. This view was sum ma rized recently in a report by the august U.S. National Academy of Each passing year has seen our estimates of the probability of life in space increase, along with our capabilities of detecting it. More and more scientists feel that contact with other civilizations is no longer something beyond our dreams, but a natural event in the history of mankind that will perhaps occur within the lifetime of many of us. . . . In the long run this may be one of sciences most important and most profound contributions to mankind and to our civilization. Life, yesbut in what forms? Extraterrestrial beings alm ost cer tainly will not be humanoids. It would be too extraordinary if this planets conditions were duplicated precisely elsewhere. Our life resulted from a lengthy, delicate evolutionary process, which would have been permanently changed if any of a multitude of param eters had been different. Thus, although many scientists believe that life, even in advanced forms, probably is ubiquitous in the universe, they are equally convinced that there are no hum ans beyond Earth. In Loren Eiseleys words: * * * nowhere in all space or on a thousand worlds will there be men to share our loneliness * * * Of men elsewhere and beyond, there will be none forever. Even in a fertile cosmos, life here remains unique and precious. Biochemists believe that of the 100 plus elements known to man, only one can be the basis of life, here or elsewherecarbon. Given that terrestrial life consists of aggregates of complex carbonaceous polymers, such an assertion may appear chauvinistic; actually it reflects nature itself. Carbon is the only known element capable of forming the intricate molecules so seemingly essential to anything approximating life as we understand it [fig. 1], Figure 1.The Creation of Man from the Cappella Sistina. The insightful question about the genesis of life on Earth is not, Was it m iraculous? but rather, Was it unique? In the 1920s the biochemists Haldane in England and Oparin in Russia independently suggested that organic compounds could be produced from elementary inorganic molecules. Increased knowledge about the Earths primordial atmosphere indicated that it had contained appropriate ingredients for the origin of lifehydrogen, ammon- onia, methane, water vapor. Then, in the early 1950s, Miller and Urey dram atically showed that these molecules would form amino acids if subjected to a laboratory simulation of the Earths early conditions [fig. 2]. Figure 2.Miller/Urey synthesis of amino acids. Subsequent research supports the conclusion that life likely will arise spontaneously, given the right initial situation. Of course, if we are wrong on this, irrespective of the cosmoss vastness, we could be alone. Even though terrestrial life now is hearty and adaptable, any one of a multitude of possible calamities could have prevented our development, such as inadequate supply of terrestri al water, severe irregularities in solar luminosity, major dynamical perturbations by the Moon or planets, or collision with another astronomical object. Our biological beginnings may have been spe cial, even unique; or perhaps no other suitable habitat exists. But besides the philosophical repugnance of this egocentric view, modern findings seem contrary. Therefore, many of us believe that, under reasonable conditions, chemical and biological evolution will be inevitable. And, although the appearance of extraterrestrials may be wildly different from our own, their chemistry will be at least remotely similar. If this last assumption is false, then the following statements will consti tute a conservative lower bound; that is, if noncarbon based life is possible, the overall prevalence of life will be even greater, [fig. 3]. Figure 3.Mars, as photographed in 1909. O f all the celestial objects, the one that for the longest time has prompted m an to wonder if he is alone is the enigmatic Mars. Like Earth, it has seasons during which its polar caps shrink in the spring, while its equatorial regions darken as if vegetation were being nourished by m elting liquids [fig. 4], Figure 4.Lowells map of Martian canals, c . 1900. And in 1877, a leading Italian astronomer reported sighting long rectilinear features on the M artian surface canali, or channels. This innocuous term was later Anglicized to canals, which im plies intelligent intervention. A t the turn of the century, the quest for M artian life was championed by Percival Lowell of the promi nent Boston fam ily; and, in the early 1920s, Marconi reportedly detected M artian radio signals. Moreover, on the evening of 21 August 1924, as Earth and M ars passed exceptionally close to one another in their elliptical orbits, m any radio stations worldwide ceased broadcasting for several m inutes each hour in order that M artian radio signals might be detected. Another impetus to the M artian intrigue arose in the m id-1930s, when a clergym an read a story over British radio alleging that communists were invading the countryside. That this fictitious ac count should elicit widespread consternation prompted a perspica cious young Am erican radio producer to employ a sim ilar ruse but with creatures even more terrifying than communistsM artians. This led to the famous radio hoax in 1938. Due to local atm ospheric turbulence, ground-based astronomy from Earth cannot provide a definitive answer about the nature of M arss surface; hence, an in situ experim ent was needed. In 1971, our understanding of M ars changed dram atically as a N A SA probe returned by far the best photographs seen of the planet until that tim e [fig. 5], Figure 5.Mariner 9 view of Martian canyon system, roughly four times the depth of our Grand Canyon and as long as from California to New York. Although they did not settle the question of M artian life, they revealed a fascinating world, with gargantuan volcanos and colos sal canyons. The fabled canals were revealed to be nothing more than undulating natural depressions, and the equatorial darken- ings were explicable without life forms. Still, we do not know about the possible presence of microscopic M artian life. The rigors of M ars would make life difficult although not insuperable. N A SA s Viking mission has been stupendous but m any questions rem ain. If even elem entary life forms were discov ered on M ars or elsewhere in the solar system, we would be embol dened, for the presence of two life-supporting objects about a single star would strongly im ply prevalence elsewhere. But our discussion today focuses on intelligent extraterrestrial life, and that unquestionably implies a search outside our solar To proceed, let us assume that life will arise only, if not reside perm anently, on planets, not in interstellar gas clouds or else where. Again, if we were wrong on this, our estim ates would be too conservative [fig. 6]. Figure 6.Mosaic of the Milky Way. Our story now must turn to the planetss parents, the stars. Our Sun is one of more than 250 billion stars composing the Milky Way galaxy, in a universe containing tens of billions of galaxies. In fact, there are more stars in the heavens than there are grains of sand on the beaches of Earth. Of these multitudes of stars, which might make suitable parents for life-supporting planets? A candidate star should be moderately luminous, roughly like the Sun. Extremely luminous stars burn nuclear material so rapidly that their life times are mere fractions of the Suns; hence, life near them prob ably would have insufficient time to undergo the arduous process of evolution. In contrast, extremely under-luminous stars burn slowly, permitting biological evolution; but their ecospheres, or habitable zones, would be small, requiring potentially life-support ing planets to orbit so close that they would be forced to keep one face perpetually toward the star, thereby evaporating their atmos phere on one side while freezing it on the other. A candidate star should also be temporarily stable; it should not pulse in size, or erupt, or throw off gaseous shells, or spin frantically. Therefore, we omit as prime candidates such objects as variable stars, novae, planetary nebulae, and pulsars [fig. 7]. Figure 7.Planetary nebulaan ultra hot central star, shedding a vast shell of The planets themselves must not undergo dynamical perturba tions. Roughly half the stars in our galaxy are members of m ulti ple systems in which two or more stars lock gravitationally and orbit each other. Planets around a member of such a system might be perturbed by the other star. To be cautious, let us discard all multiple star systems as being dangerous abodes for life [fig. 8], Figure 8.Binary star system. The next question is whether any of the suitable stars actually possess planets. Several independent lines of evidence suggest they do. Theory indicates that stars form by condensing gravitationally from the gas and dust that lace throughout a galaxys spiral arms. As such a nebula contracts, apparently it can split into clumps of different mass: a large one with several small companions, leading to a single star with planets; or several of comparable size, leading to a multiple star system. In principle, a substantial fraction of the suitable stars could possess planets [fig. 9]. l g r; S p P a t h o f s t a r ? w ith o u t Figure 9.Perturbation of a stars motion by an orbiting planet. And planets appear to be observed orbiting some of the stars nearest the Sun. Interstellar distances are so vast that a Jupiter, much less an Earth, would scarcely be visible directly at even the nearest star. Planets can reveal themselves indirectly, though, by the minute wiggle their gravitational pull causes in the path of their parent star. After decades of painstaking observations, such perturbations seem to have been detected for a few nearby stars. (The measured size of these shifts, incidentally, is about the same as a hairs angular diameter as seen at one mile.) The planets appear to exist, but are the requisite chemicals available? Even though chemical analysis of these planets atmos pheres lies far beyond our present capability, in the past few years radio astronomers have discovered numerous forms of interstellar molecules, including biologically significant ones. Considering that the planets formed in such an environment, it seems highly plausi ble that their atmospheres contain the substances necessary for biochemical evolution. Hence, we now strongly believe that the suitable parent stars exist, the planets exist, the chemicals exist, the necessary conditions exist. But does all that imply that extra terrestrial life exists? [Fig. 10.] Figure 10.Number of extant communicative civilizations in our galaxy roughly equals (rate of star formation) (fraction of stars with planets) (number of those that are ecologically suitable for life) (fraction on which life originates and evolves) (fraction